spectrometry. This robust analysis, validated with other geochemical complex mixtures, such as petroleum, allows for the observation of the size and three-dimensional structure of detected species. By comparison, with standards molecules, we exclude several structures such as pure PolyHCN and pure polycyclic aromatic hydrocarbons to be present in the principal trend of the laboratory tholins. Using theoretical calculations, we propose a plausible structure consistent with our results, which is a branched triazine-pyrazole. We observe that the larger the aerosols molecules are, the more they tend towards a structure containing small aromatics cores linked together by short chains. We suggest that the use of such an analytical approach could help advance our understanding of other complex organic compounds in the Solar System such as soluble organic matter in meteorites.

Manda, S., Punekar, J., 2020. Experimental validation of the planktic foraminifera fragmentation index as proxy for the end-Cretaceous Ocean Acidification. Marine Micropaleontology 155, 101821.

http://www.sciencedirect.com/science/article/pii/S0377839819301033 The final ~50 ky of the Maastrichtian leading up to the Cretaceous-Paleogene (K-Pg) boundary mass extinction at Bidart (France) and Gamsbach (Austria) record poor carbonate preservation indicative of ocean acidification preceding the mass extinction. Further evidence includes enhanced planktic foraminifera test fragmentation, anomalously low bulk-rock magnetic susceptibility (acidification) and peak mercury content (toxicity) related to peak Deccan volcanism in India. Here we present new experimental data that validates the Fragmentation Index of planktic foraminifera as a reliable proxy for the end-Cretaceous acidification. Pristine Cretaceous planktic foraminiferal shells (from DSDP 525A, palaeodepth ~1000 m) were exposed to buffers of pH 8.0, 7.5, 7.0 and 6.5 for 15 days each, and their preservation state was quantified as a function of time. The critical variables affecting test taphonomy are morphology, pH and time of exposure. Thin-walled Heterohelix fragile biserial species constitute an average ~60% of typical Late Maastrichtian assemblages (e.g globulosa H. planata and ) and are most susceptible to dissolution, followed by simple coiled forms such as Rugoglobigerina Hedbergella sp. (~19% of the assemblage) and sp. (~6% of the assemblage). The Globotruncana, Globotruncanita globotruncanids ( , ~12%) are least susceptible to chemical and physical damage. Lower pH conditions render tests more vulnerable to physical fragmentation. Caution is needed to assess taphonomic inflation of morphologically robust yet environmentally sensitive Cretaceous species (e.g. globotruncanids), that may result in an underestimation of the degree/nature of the faunal crisis and tempo of extinctions in the pre-extinction acidification interval.

Mansoori Mosleh, F., Mortazavi, Y., Hosseinpour, N., Khodadadi, A.A., 2020. Asphaltene adsorption onto carbonaceous nanostructures. Energy &Fuels 34, 211-224.

https://doi.org/10.1021/acs.energyfuels.9b03466 The adsorption of asphaltene onto different carbonaceous nanostructures including reduced graphene oxide (rGO), multiwall carbon nanotubes (MWCNTs), carbon black (CB), and activated carbon (AC) was studied. Graphene oxide was synthesized via Hummers' metho d and reduced in a thermal shock to prepare rGO. Asphaltene was extracted from a heavy oil sample and characterized. The textural and structural properties of the carbonaceous nanostructures were characterized by Brunauer - Emmet - Teller surface area measurement, field-emission scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and temperature-programmed desorption. Asphaltene was dissolved in a solution of 37 vol %heptane in toluene (Heptol) to prepare heavy oil model solutions. The carbonaceous nanostructures were added to the model oils, and the kinetics as well as the equilibrium adsorption and desorption of the asphaltene onto the adsorbents were studied. The pseudo-second-order kinetic model best explains the asphaltene adsorption onto the carbonaceous adsorbents. The time required to approach equilibrium adsorption of the asphaltene is 1, 4, 12, and 24 h over rGO, MWCNTs, CB, and AC, respectively. The adsorption isotherm of the asphaltene onto rGO follows Langmuir model, while Freundlich isotherm bets fits the asphaltene equilibrium adsorption onto MWCNTs and CB. Among the carbonaceous adsorbents, the rGO sample exhibits the highest asphaltene adsorption capacity of 640 mg/g, about 5.7, 2.4, and 1.2 times as high as that of AC, CB, and MWCNTs, respectively. The adsorption of the asphaltene onto AC is found to be diffusion-limited. This is ascribed to the micropores present in the AC